Applies To:
  • CitectSCADA 6.xx, 7.00
  • CitectHMI 6.xx, 7.00

The CSV_INCLUDE module CSV_Database() allows you to specify a standby database if there is a problem with the primary database. This standby function did not work and so the standby database was never used. 

If the procedure call to retrieve the data for the current query fails, the corrected version of CSV_Database() now switches to the 2nd database from that point onwards. The basic failover/failback approach used is to use the primary until such time as it becomes unavailable and at that time, we swap to the standby database indefinitely. In the event of a failure accessing the standby database, we swap back to the primary and so on.

The reason for this ‘bistable’ approach is that it can take a long time (10s of seconds or minutes in some cases) so it is worthwhile avoiding connection attempts to a database which was not operating on the previous call.

Citect has confirmed this to be a problem in CitectHMI/SCADA versions 5.50 to 6.10SpkB. This problem has been fixed in version 7.0.


CSV_Include CSV_Database standby database failover